Showing papers by "University of Miami published in 1972"
TL;DR: In this article, the authors show that dust-laden heated air emerges from West Africa as a series of large-scale anticyclonic eddies which move westward over the tropical Atlantic above the trade-wind moist layer, principally in the layer between 5000 and 15,000 ft (600-800 mb).
Abstract: The intense and prolonged heating of air passing over the Sahara during the summer and early fall months forms a deep mixed layer which extends up to 15–20,000 ft during July, the warmest month. The dust-laden heated air emerges from West Africa as a series of large-scale anticyclonic eddies which move westward over the tropical Atlantic above the trade-wind moist layer, principally in the layer between 5000 and 15,000 ft (600–800 mb). Measurements made during BOMEX show that this Saharan air is characterized by high values of potential temperature, dust and radon-222 which confirm a desert origin. As the parcels of air within the layer proceed across the Atlantic the continuous fallout of particulate matter and the mixing at the base of the layer cause dust to be transferred to the lower levels where its concentration may become sufficiently great to produce dense haze at the surface over wide areas over the Atlantic and Caribbean in the latitude belt 10–25N. Nevertheless, measurements indicate ...
641 citations
TL;DR: It is stressed that AP was found to be more reliable than PABs in eliciting an abnormal response and thereby aids in the diagnosis of the “sick sinus syndrome.
Abstract: The phenomenon of postpacing depression of cardiac pacemakers was utilized to evaluate the sinus-node function in 56 patients by analyzing the sinus-node recovery time (SRT), that is, the interval between the last paced P wave and the following sinus P wave. Corrected SRT (CSRT) is defined as the recovery interval in excess of the sinus cycle (SRT — sinus cycle length). The SRT was measured following sinus-node suppression by (1) isolated premature beats (PABs) and (2) atrial pacing (AP) at rates of 100 to 140/min for periods of 2 to 5 min at each level. Twenty-eight patients had normal heart rates (group A), and 28 patients had sinus bradycardia (SB; group B). Ten of the 28 patients with SB were restudied after receiving atropine (2 mg intravenously). The CSRT with PABs was similar in both group A and group B patients and remained essentially unchanged after atropine despite a decrease in sinus cycle length. The phenomenon of interpolated PABs was demonstrated in seven of the 56 patients. In 27 of the 28...
480 citations
TL;DR: Using La3+ to eliminate extracellular bound Ca2+ from calcium-influx measurements showed that depolarization by high K+, Na+ replacement, and high pH activate smooth muscle contraction by stimulating Ca2- influx.
Abstract: Lanthanum inhibits 45Ca efflux from internally injected squid axons. Evidence for La3+ blockade of Ca2+ fluxes across the cell membrane was also obtained for aortic smooth muscle: 1mM La3+ completely inhibited contractions which otherwise resulted from adding Ca2+ to calcium-free depolarizing solutions, and 2 mM La3+ caused a 50% inhibition of the late 45Ca efflux. Ca2+ bound extracellularly could be displaced by La3+, and the binding sites preferred La3+ over Ca2+. We could thus use La3+ to eliminate extracellular bound Ca2+ from our calcium-influx measurements as follows: after exposure of the aortic strips to experimental solutions labeled with 45Ca, the extracellular Ca2+ label was displaced by putting the strips in a calcium-free solution containing 2 mM La3+ for 60 minutes. The loss of intracellular Ca2+ was minimized during this hour by the La3+ blockade of Ca2+ membrane fluxes. Tissue weight, 45Ca, and total Ca2+ were then measured using standard techniques. Studies employing this new method showed that depolarization by high K+, Na+ replacement, and high pH activate smooth muscle contraction by stimulating Ca2+ influx. Low pH and La3+ block Ca2+ influx. Norepinephrine initiates aortic contractions by release of intracellularly sequestered Ca2+. Angiotensin and histamine appear to release Ca2+ from this same fraction.
436 citations
TL;DR: The phenol-sulfuric acid method for determining total carbohydrates was applied to surface sediment samples from a brackish water lake, using an improved technique in which the order of addition of reagents proved to be essential for reproducibility.
Abstract: The phenol-sulfuric acid method for determining total carbohydrates was applied to surface sediment samples from a brackish water lake, using an improved technique in which the order of addition of reagents proved to be essential for reproducibility. Corrections are made for noncarbohydrate materials that may be present in the samples.
254 citations
206 citations
TL;DR: The sequence of conduction through the intraventricular conducting system and endocardial muscle was studied by microelectrode mapping of large areas of isolated canine ventricular tissue and it was found that most of the endocardium of the right ventricular free wall is activated simultaneously whereas the left endocardia is activated in an apex-to-base sequence.
Abstract: The sequence of conduction through the intraventricular conducting system and endocardial muscle was studied by microelectrode mapping of large areas of isolated canine ventricular tissue. We found that most of the endocardium of the right ventricular free wall is activated simultaneously whereas the left endocardial muscle is activated in an apex-to-base sequence. Right septal activation is from apex to base, and the left septum is activated first at the junction of the middle and lower thirds of the septum and then as a bidirectional wave front toward the apex and the base. These right-left differences occur because the sites of impulse input into muscle on the right encompass the entire free wall, base of the papillary muscle, and the lowermost septum, and on the left are primarily limited to the lower ventricular cavity, lower septum, and bases of the papillary muscles. These patterns of left ventricular excitation relate to the presence of a functionally continuous ring of conducting tissue formed by a merger of the major divisions of the left bundle branch on the upper left ventricular free wall. The "ring" itself is electrophysiologically isolated from muscle, but connects to a network of subendocardial conducting tissue extending to the apex and having input to muscle only in its lower portions.
203 citations
TL;DR: An explanation for the discrepancy between the effectiveness of the antibiotics in the two phase system and the transport rates in sarcoplasmic reticulum is provided by the observation of a particularly low affinity of X537A for Ca++ and Sr++ in polar media.
181 citations
TL;DR: The convulsant alkaloid bicuculline blocked presynaptic inhibition, dorsal root potentials, primary afferent depolarization, and depolarizing effects of gamma-aminobutyric acid on dorsal root terminals of the amphibian spinal cord, but did not block effects of other putative amino acid transmitters.
Abstract: The convulsant alkaloid bicuculline blocked presynaptic inhibition, dorsal root potentials, primary afferent depolarization, and depolarizing effects of gamma-aminobutyric acid on dorsal root terminals of the amphibian spinal cord, but did not block effects of other putative amino acid transmitters. These actions of bicuculline suggest that gamma-aminobutyric acid may be the transmitter involved in spinal presynaptic inhibition.
174 citations
TL;DR: The possible rotes of “pre-packaging” and visual, proprioceptive and internal prenuclear feedback in the generation of CMs are discussed and it is concluded that a prenuclear internal monitor best accounts for glissadic CMs whereas saccadic C Ms may be explained by either proprioception feedback or an internal monitor.
161 citations
TL;DR: It is concluded that the time taken by a cell to travel to the surface, once it has been formed, is probably 40‐56 days in normal skin, and 6‐8 days in psoriatic skin.
Abstract: SUMMARY.— The literature on the turnover or renewal time of normal and psoriatic epidermis is critically reviewed. It is concluded that the time taken by a cell to travel to the surface, once it has been formed, is probably 40-56 days in normal skin, and 6-8 days in psoriatic skin.
156 citations
TL;DR: Several additional compounds have been identified from orchid floral fragrances, some of which have been demonstrated in field tests to be active attractants of male euglossines, while other compounds have be shown to modify or reduce the attraction potential of various other odor components.
Abstract: It has been known for some time that male bees of the tribe Euglossini visit and often pollinate various orchid flowers (Dodson and Frymire, 1961a, 1961b; Dodson, 1962, 1967; Vogel, 1963, 1966; van der Pijl and Dodson, 1966; Dressler, 1967, 1968a, 1968b). The syndrome of "euglossine pollination" was discussed by Dressler (1968b). He noted that the orchid flowers that are pollinated exclusively by male euglossine bees are very fragrant, but are almost always lacking in nectar; therefore, no food is present. The source of the attraction was recognized as the fragrance of the flower, but the identity of the odor components was not known for a number of years. Eleven compounds from orchid floral fragrances were identified (Hills et al., 1968), but only some of the compounds were shown to be attractants of male euglossine bees (Adams, 1968; Dodson et al., 1969). Adams showed that some of the compounds from orchid fragrances modified the attraction potential of other fragrance components, and that some of the compounds were not attractive to male euglossine bees. Several additional compounds have been identified from orchid floral fragrances (Dodson and Williams, unpublished), some of which have been demonstrated in field tests to be active attractants of male euglossines, while other compounds have been shown to modify or reduce the attraction potential of various other odor components. The behavior of the bees on the flowers and at the isolated odor components has
TL;DR: The results suggest that the effects of PGE(2) in clearing the scales may be associated with its inhibitory effect on abnormal sterol esterification in the skin of the EFA-deficient rats.
TL;DR: The body's capacity to store relatively large quantities of gold without adverse reaction is demonstrated, support the concept of a systemic rather than local mechanism of action (at the joint level) and in vivo gold concentrations in the range expected to produce local cellular biologic effects are demonstrated.
Abstract: Postmortem specimens from a patient with rheumatoid arthritis who had received 5 g of aurothioglucose were examined histologically, and their gold content was determined by activation analysis. The highest concentration of gold was found in the lymph nodes followed by the adrenal gland, renal cortex and other organs of the reticuloendothelial system. Comparatively low concentrations were found in tissues comprising the joint structure. Organs in which the greatest quantities of gold were stored include the bone marrow, liver, skin and bone. These findings demonstrate the body's capacity to store relatively large quantities of gold without adverse reaction, support the concept of a systemic rather than local mechanism of action (at the joint level) and demonstrate in vivo gold concentrations in the range expected to produce local cellular biologic effects.
TL;DR: Exploratory celiotomy has been evaluated for surgical staging of cervical cancer prior to therapy and it was revealed that clinical staging was inaccurate in 38.6 per cent of patients studied.
01 Mar 1972-Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology
TL;DR: The results clearly indicate that resistance reflexes do not play an important role in coordination of antagonistic muscles during walking and it is likely that their primary function is to compensate for changes in the load applied at a joint as would occur on steep inclines and irregular surfaces.
Abstract: 1.
Discharge patterns in the motoneurons innervating the propodite stretcher and bender muscles and dactylopodite opener and closer muscles of the legs of the land crab, Cardisoma guanhumi, were recorded during sideways walking on a styrofoam wheel (Fig. 1).
2.
Rhythmic bursts of activity in these motoneurons can be correlated with leg movements during walking in both leading and trailing legs (Figs. 2, 3A, B, D). Similar patterns of activity can be recorded in animals freely walking on a bench (Fig. 3C).
3.
These motor output patterns are quite different from those occurring in the same motoneurons during resistance reflexes. In particular, the shared openerstretcher excitor and the stretcher inhibitor show no preferential phase relationship during walking (Figs. 4, 5). It appears that the normal movements of the propo-dactylopodite (P-D) joint during walking do not give rise to resistance reflexes.
4.
Opening and closing movements of the P-D joint, manually imposed during walking, induce resistance reflexes (Figs. 6, 7). Reflexes tend to be stronger, both in terms of number of impulses and impulse frequency, when the imposed movement opposes rather than reinforces ongoing P-D movements.
5.
Animals walking sideways on the wheel with the P-D joint clamped rigidly in a stable position show only slight changes in their motor output patterns from those seen during normal walking (Fig. 3E).
6.
A model is discussed in which the proprioceptive input resulting from the normal movements of the P-D joint during walking is inhibited centrally and so does not give rise to a resistance reflex.
7.
These results clearly indicate that resistance reflexes do not play an important role in coordination of antagonistic muscles during walking. Instead it is likely that their primary function is to compensate for changes in the load applied at a joint as would occur on steep inclines and irregular surfaces.
TL;DR: It appears that estrogen preparations investigated did not consistently or significantly alter carbohydrate metabolism, and it seems that metabolism alterations reported are due to progestogens alone or from a synergistic effect of estrogen and progestogen.
TL;DR: Experiments with seedlings grown under hypobaric conditions suggest that the gas naturally controls plumular expansion and cell division in the apical region of etiolated Pisum sativum (var. Alaska) seedlings.
Abstract: Ethylene and supraoptimal levels of 2,4-dichlorophenoxyacetic acid inhibit the growth of the apical hook region of etiolated Pisum sativum (var. Alaska) seedlings by stopping almost all cell divisions. Cells are prevented from entering prophase. The hormones also retard cell division in intact root tips and completely stop the process in lateral buds. The latter inhibition is reversed partially by benzyl adenine. In root tips and the stem plumular and subhook regions, ethylene inhibits DNA synthesis. The magnitude of this inhibition is correlated with the degree of repression of cell division in meristematic tissue, suggesting that the effect on cell division results from a lack of DNA synthesis. Ethylene inhibits cell division within a few hours with a dose-response curve similar to that for most other actions of the gas. Experiments with seedlings grown under hypobaric conditions suggest that the gas naturally controls plumular expansion and cell division in the apical region.
TL;DR: The fluorescence changes associated with metabolic alterations are shown to arise partly from cation transport and partly through alterations in the binding properties of the inner surface of the membrane.
Abstract: The use of the fluorescent chelate probe, chlorotetracycline, in mitochondria is described. The probe shows a high fluorescence in the presence of mitochondria which may be ascribed to binding of the probe to membrane-associated Ca(++) and Mg(++). The fluorescence excitation and emission spectra are diagnostic of binding of the probe to Ca(++) in coupled mitochondria and Mg(++) in uncoupled mitochondria. The fluorescence polarization spectra are diagnostic of the cations having a moderately high mobility in the membrane environment. The effects of exogenous EDTA and of endogenous Mn(++) indicate that the probe is primarily visualizing actively accumulated Ca(++) on the inner surface of the inner membrane. By employing the Ca(++) transport inhibitor, Tb(+++), the fluorescence changes associated with metabolic alterations are shown to arise partly from cation transport and partly through alterations in the binding properties of the inner surface of the membrane. Chlorotetracycline is a probe for divalent cations associated with the membrane and is of general utility in the study of cation migrations in cellular and subcellular systems.
TL;DR: It is recommended that the generic term “ceruminoma” be retained for apocrine tumors arising in the external auditory canal.
Abstract: Light and electron microscopic features of a case of ceruminous adenocarcinoma are presented and compared to normal ceruminous glands. A survey of the literature disclosed 4 types of ceruminoma: adenoma, adenocarcinoma, adenoid-cystic carcinoma, and mixed tumor. The pathogenesis and histologic features of each type are discussed. Because biologic activity varies with the histologic pattern, and because of the greater frequency of malignancy as compared to other cutaneous apocrine tumors, it is recommended that the generic term “ceruminoma” be retained for apocrine tumors arising in the external auditory canal.
TL;DR: The index theorem of Gohberg and Krien on Weiner-Hopf operators on the unit circle was generalized in this paper, where it was shown that the index of the operator S is equal to (−1)n time degree of the restriction of s to ∂Ω, if N ⩾ n.
TL;DR: In this article, the graphite atomizer has been evaluated for direct injection analysis of sea water for trace transition metals and was found to be impossible due to the scattering interference of the major salts.
TL;DR: Theoretical considerations suggest that, for optimal resolution in determination of exchange coefficients and advection rates in the ocean thermoclines, a radioactive tracer should have a mean life of about one-tenth of the characteristic system relaxation time.
TL;DR: In this paper, the authors describe the social organization of two comparable colonies of bicolor damselfish, Eupomacentrus partius (Poey), at various times of the year.
Abstract: The social organization of two comparable colonies of bicolor damselfish, Eupomacentrus partius (Poey), is described at various times of the year. A small laboratory colony (8 adults) was observed during two different social phases. The first included the initial establishment of dominant-subordinate relationships among its members, as well as the establishment of the general spatial distribution of fish within the aquarium. The second phase was characterized hy a high level of territoriality and reproductive activity. A field colony of similar size (9 adults, 4 juveniles) was observed by SCUBA and underwater television also during the reproductive phase. This colony was located 1.5 km off the west coast of North Bimini, Bahamas and at a depth of 20 m. The social structure of both colonies was characterized by a straight-line, nip-dominant hierarchy which was stable and largely size-dependent. Aggressiveness and maleness also appeared to play important roles in the dominance relationships. Differences in the distribution of chases and challenges recorded from the laboratory colony during the two differing social phases indicated that dynamic processes were underlying the basic social structure of both colonies. Little or no diurnal fluctuation in aggressiveness was apparent during the two phases studied in the laboratory. The level of chasing activity throughout the day, however, was well correlated with hierarchical rank during the initial phase of observations, but such was not the case during the later phase. The initial phase was also characterized by closely ranked individuals directing most "attention" at one another, while during the later reproductive phase, much of this "attention" was directed at the Omega fish. It appeared as if the Omega was playing the role of a "scapegoat" for the directed aggression of higher ranking members and thereby relieving aggressive tension among those members of the colony. A similar phenomenon, operating in the field colony, was also indicated by limited data. The important role of prior residence within a colony and within a specific area is illustrated by examples from the field. Finally, evidence is brought forth to suggest that interspecific aggression. although seldom studied, is a most important factor in the lives and habits of animals living within the reef community.
TL;DR: Serial blood pressure measurements were made on 415 women who were normotensive, given intrauterine devices, oral contraceptives, estrogens, or progestogens, and none of the control, progestogen, or conjugated estrogen women developed hypertension.
TL;DR: The demonstration of postoperative myocardial contractile abnormalities in previously normal patients suggests an intraoperative cause, perhaps related to cardiopulmonary bypass, and postoperative dysfunction may exist preoperatively and remain unchanged.
Abstract: Seventy-one patients undergoing valve replacement surgery were studied before and after operation to determine change of clinical condition and ventricular contractility. Preoperatively, all patients had functional class III or IV disease (New York Heart Association classification) and 55 percent had myocardial dysfunction. Post-operatively, the condition of 86 percent of patients improved clinically by at least 1 functional class, but 56 percent of patients had myocardial dysfunction. Cardiac index and left ventricular end-diastolic pressures were closely related to changes in angiographically determined myocardial contractility. Neither patient age, sex, duration of cardiopulmonary bypass, residual uncorrected valve disease nor coronary artery disease alone determined the degree of impairment in left ventricular contractility. A high incidence of myocardial dysfunction was found pre- and postoperatively in this study. In 16 patients with pure mitral stenosis, 6 (38 percent) had left ventricular dysfunction preoperatively, demonstrating intrinsic myocardial disease, possibly chronic rheumatic myocarditis. The demonstration of postoperative myocardial contractile abnormalities in previously normal patients suggests an intraoperative cause, perhaps related to cardiopulmonary bypass. Postoperative dysfunction may (1) exist preoperatively and remain unchanged, (2) occur intraoperatively, or (3) exist in a latent form preoperatively but be aggravated by the stress of surgery. Without both pre- and postoperative microscopic examination of the myocardium in the same patient, it is impossible to determine which process is primary.
TL;DR: The data indicate that cyclic adenosine 3',5'-monophosphate may be involved in regulating acetyl-CoA incorporation into de novo fatty acid and cholesterol in a specific manner in mammalian liver.